Extraskeletal osteoma in a cat.

This paper describes a case of a benign osseous lesion which arose in the right front leg of an 8-year-old spayed female cat. The growth was situated in the dermal tissue above the olecranon, but not attached to it, and shelled out easily at surgery. While certain non-neoplastic lesions, such as hamartomas or cases of heterotopic ossification, may appear histologically similar, the present case was considered to be a true tumour on the basis of the clinical, macroscopic and histological findings, and was termed an osteoma. The cat is remaining under observation, but there had been no recurrence 3 1/2 months after surgery.